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Flashcards in Sensory Receptors 2 Deck (18)
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1
Q

What are 3 types of proprioceptors and their function?

A

Muscle spindles monitor muscle length and rate of change
Golgi tendon organs monitor tension on tendons
Joint receptors monitor joint angle and rate of angular movement

2
Q

What 3 things to proprioceptors do?

A

Control voluntary movement
Send info for spinal cord reflexes
Send sensory information to perceive limb and body position

3
Q

What is another name for “Send sensory information to perceive limb and body position”?

A

Kinaesthesia

4
Q

Most contractile skeletal muscle fibres are ______ but there are some intrafusal muscle fibres with ______ sensory and motor innervation.

A

Extrafusal, specialised.

5
Q

What do intrafusal muscle fibres form?

A

Muscle spindles which lie in parallel with muscle fibres.

6
Q

______ motor neurons cause extrafusal muscle to contract and ______ motor neurons for intrafusal.

A

Alpha, gamma.

7
Q

Define nuclear bag fibres.

A

Bag shaped and nuclei collected together.

8
Q

Define nuclear chain fibres.

A

Nuclei lined up in a chain.

9
Q

What nerves spiral round the centre of intrafusal fibres to form annulospiral endings?

A

Primary endings from Ia afferent nerves.

10
Q

What nerves spiral round the centre of intrafusal fibres to form flower-spray endings?

A

Secondary endings from type II afferent nerves.

11
Q

What do the ends of intrafusal fibres have that the centres don’t?

A

Contractile sarcomeres.

12
Q

What happens when stretch sensitive channels open?

A

It creates a local generator potential, causing a regenerative action potential in afferent fibres.

13
Q

What is joint movement organised by?

A

Groups of muscles working in opposition.

14
Q

What do the nerve endings of golgi tendon organs mingle with?

A

Tendon bundles at the end of muscles.

15
Q

Why doesn’t passive stretch affect tendons?

A

They are fairly inelastic.

16
Q

Define isometric twitch.

A

A twitch where the muscle stays the same length.

17
Q

Muscle spindles lie in ______ with extrafusal muscle fibres whereas golgi tendon organs lie in ______.

A

Parallel, series.

18
Q

Why is gamma motor innervation required?

A

So the muscle spindle doesn’t go floppy when the muscle contracts or stop spindle discharges.